Internal combustion engine overload and underload alarm



April 1957 J. P. ARMSTRONG ETAL 2,790,163

INTERNAL COMBUSTION ENGINE OVERLOAD AND UNDERLOAD ALARM Filed Jan. 10, 1955 A TTORNEYS.

States INTERVAL COMBUSTION ENGINE OVERLOAD AND UNDERLOAD ALARM John Percy Armstrong and John Donald Hofipaui Orange, Tex.

This invention relates to an alarm system for indicating overload and underload conditions of internal combustion engines such as diesel engines and the like. It has particular advantage where the operator of an internal combustion engine has a remote station which is not within sight or hearing of the engine.

It is an object of this invention to provide a completely automatic alarm system which may be connected to an internal combustion engine to indicate any overload or underload condition of the engine. Another object of this invention is to provide controlling valve means for operating such an alarm system from the lubricating oil pressure of the internal combustion engine. Other objects and advantages of this invention, including the simplicity and economy of the same, will further appear hereinafter.

The drawing represents a schematic view of one specific form of overload and underload alarm system which embodies features of this invention.

Turning now to the specific embodiment of the invention selected for illustration in the drawing, it will be.

appreciated that the system is connected to an internal combustion engine (not shown) which has a conventional speed governor and fuel feed metering means which is movable in response to engine load to increase anddecrease the engine fuel feed rate. Such means are entirely conventional and constitute of themselves no part of this invention, and are accordingly not particularly illustrated atent G in the drawing. However, it will be appreciated that the fuel metering means includes a shaft 1, to which 18 connected an actuating arm 2 which is connected through an adjusting screw 3 to a plunger 4'which is axially reciprocable within a substantially cylindrical valve body 5. The valve body 5 has an inlet port 6 which is connected through a pipe or tube 7 to a source of pressurized lubricating oil, which pressure may be applied by a lubricating oil pump 10 or the like. The pump 10 may be a part of the internal combustion engine or separate.

The number 11 designates a piston member which is axially reciprocable within a central cylindrical bore 12 axially extending within the valve body 5. At one end the piston has an enlarged cylindrical valve member 13 and at the other end is a similar cylindrical valve member 14. Spaced axially between the valve members 13, 14 the piston member 11 is undercut to provide a cylindrical passage 15 between the piston and the valve body 5. The plunger 4 is mechanically connected to one end of the piston member 11 at the cylindrical valve member 14. At its other end the piston member 11 has a stud 16 forming a base for a helical compression spring 17. A drain tube 20 is connected into the end of the bore 12 adjacent the spring 17, and extends to the engine sump.

The numbers 21 and 22 designate respectively axiallyspaced outlet ports which extend through the valve body 5. In an axial sense, the inlet port 6 is intermediate the outlet ports 21, 22. The outlet port 21 is connected by means of a pipe 23 to an inlet orifice 24 of an accumulator 25. The accumulator has an outlet orifice 26 2,790,163 Patented Apr. 23, 1957 which is connected by pipe 27 to the drain leading to the engine sump. The accumulator is also connected by a pipe 30 to a pressure switch 31 connected electrically to an overload alarm light 32, which may be colored red, for example. The pressure switch 31 is also connected electrically to an overload alarm buzzer 33.

The outlet port 22 is connected to a pipe 34 to an inlet orifice 35 of an accumulator 36. The accumulator 36 has an outlet orifice 37 which is connected by a pipe 40 to the drain to engine sump. The accumulator 36 is also connected by a pipe 41 to a pressure switch 42 which is electrically connected to an underload alarm light 43, which may be colored green for example. It will be appreciated that the switches 31, 42 may be conventionally hydraulically-actuated electric switches of any appropriate design. The specific construction and operation of the switches is not, of itself, part of this invention and is not shown in particular detail in the drawing.

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In operation, the actuating arm 2 of the fuel metering rack moves back and forth in the manner indicated by the dash arrows in the drawing, in response to changes of load of the internal combustion engine. The plunger 4 correspondingly reciprocates, causing the piston member 11 to reciprocate axially within the bore 12. As illustrated in the drawing, an underload condition exists, and fluid is flowing from the line 7 through inlet port 6, through the passage 15, out the outlet port 22 into the accumulator 36. Since the inlet orifice 35 is larger than the outlet orifice 37, pressure accumulates in the accumulator 36 and is transmitted to the pipe 41 to the switch 42 actuating the alarm light 43. Should the engine load increase, the actuating arm 2 moves upwardly, shifting the valve member 14 upwardly and closing the port 22. Oil bleeds out of the accumulator 36 (through the outlet orifice 37) and is returned to the engine sump thereby relieving the pressure on switch 42 and deenergizing the underload alarm light. 43. When the engine is operating under normal load, no signal is given by either light 32, 43 or the buzzer 33. If the engine load increases, the cylindrical valve member 13 moves toward a position to open the outlet port 21 while the port 22 remains closed by the valve member 14. When the outlet port 21 is opened, lubricating oil under pressure flows from the pipe 7 through inlet port 6, through the passage 15, out the outlet port 21, and through pipe 23 and inlet orifice 24 into the accumulator 25. Since the size of the opening of inlet orifice 24 is greater than the size of the opening of outlet orifice 26, pressure is built up in the accumulator 25 and is transmitted through the pipe 30 into the pressure switch 31, energizing the ggerload alarm light 32 and the overload alarm buzzer It will be appreciated that the overload and underload alarm devices are located at a position remote from the internal combustion engine, and that the operator of the engine may be provided with appropriate controls for regulating the load on the engine. 7

It will be appreciated that the valve body 5 may be axially adjusted with respect to the actuating arm 2. As shown in the drawing, the valve body 5 is supported from a bracket 44 by means of jamb nuts 45 which are threaded to an upper portion of the valve body 5. The bracket 44 is fixed to any stationary support.

Although this invention has been described with reference to one specific embodiment thereof, it will be appreciated that various modifications may be made without departing from the scope of the invention. For example, parts may be reversed, equivalent elements may be substituted for those shown and described, and certain features may be used independently of the use of other features, all within the spirit and scope of the invention as defined in the appended claims.

Having thus described our invention, we clarm:

1. An alarm system for an internal combustionengine,

which consumes liquid fuel, which enginehasagovernor and. a fuel metering rack which is constructed, and arranged, to regulate the fuel feed by moving in one. direc; tion to increase fuel feed and moving in the. opposite direction to decrease fuel feed, the combination comprising a cylindrical valve housing having an inlet opening and having a pair of spaced-apart outlet openings, means connectinglubricating oil under pressure to said inlet opening, a piston valve axially reciprocable, within said housing, said piston valve having a pair of spacedapart valve members which are arranged to move: axially to open and close, said outlet openings, means connecting said piston valve to said metering rack for moving said piston valve axially in. response to the movement of said metering rack, an overload pressure switching device, an. underload pressure. switching device, meansfor connecting, one of said outlet openingsto said overload pressure switching device, and means for connecting thev other of said outlet openings, to said underload pressure switching device.

2. In an apparatus for indicating an abnormalfload condition of an internal combustion enginev which consumesliquid fuel, Which engine includes speed governe ing means and fuel feed regulating means which is movable in response to engine load to increase and decrease engine fuel feed; rate, and which engine includes a source of lubricating oil' under pressure, the combination com.- prising valve means having an inlet hydraulically connected. to said source and mechanically connected for actuation, by said fuel feed rneteringmeans fluid accumulator means, means connecting said accumulator means, hydraulically to the outlet of. said; valve means, pressure switching; means, and means. connecting said accumulator means hydraulically to actuate said pressure switching means, said'accumulator means. comprising; an enclosure constructed to contain said" lubricatingoilreceiyed from. said source, and said: enclosure, having a drain means in. cluding an orifice of restricted. areator slowly releasing lubricating oil from said accumulator means and thereby tending to reduce the; lubricating oil. Pressure therein,

whereby, the operation, of the pressure switchingmeans is delayed with, respect to the, operation. of the fuel, feed regulatingmeans.

3, In an, apparatus for indicating; overload and underload of an internal combustion engine which consumes liquid fuel,. which engine includes speedgoverning means: and fuel feed regulating means; which is. movable in response to engine load to increase. and decrease engine fuel feed rate; and which engine. includes. a. sourcev of lubrieating oilunder pressure, the. combination comprisingvalvemeans. having an inlet. hydraulically. connected to said source" and mechanically connected for actuation by said fuel feed metering means, fiuidaccumulator means, means connecting said accumulatorw means hydraulically to the outlet of said valve means, pressure switching means, and means connecting said. accumulator means hydraulically to actuate said pressure switching means, said valve means includingtwo outletopenings, said pres- 4 sure switching means including an overload pressure switching means hydraulically connected to one of said outlet openings and an underload pressure switching means hydraulically connected to the other of said outlet openings.

In an apparatus for indicating overload and underload of an internal combustion engine which consumes liquid fuel, which engineincludesspeed governing means and fuel feed regulating means which is movable in response to engine load to increase and decrease engine fuel feed rate, and which engine includes a source of lubricating oil under pressure, the combination comprising valve. means having an inlet hydraulically connected to said source and mechanically connected for actuation by said fuel feed metering means, fluid accumulator means, means connecting said accumulator means hydraulically to the outlet of said valve means, pressure switching means and means connecting said accumulator means bydraulica-ll'y toactuate said pressure switching means, said valve meansincluding apair of spaced apart outlet openings and. furtherincluding a valve member which is movable, back, and forth. to open and close said openings, thereby maintaining either outlet opening closed with respect. to the valve inletwhen the other outlet opening is open, and an overload pressure switching means hydraulically connected to, one of said valve outlet openings and a'n-underload pressure switching means hydraulically connected to the other. of said, valve outlet openings.

5. In analarm. system for indicating an abnormal load condition of an internal combustion engine which consumes, liquid fuel, which engine includes fuel feed regulating means which. is movable in response to engine load to increase and decrease engine fuel feed rate, and which engine includes a source of lubricating oil under pressure, the combination comprising valve means connected to said lubricating oil source and connected mechanically to said regulating means. for actuating and opening said valve, when said, engine; is subjectedto-an abnormal load condition, an. accumulator having an inlet orifice and an outletorifice which issmaller than said orifice, said outlet orifice. being connected to drain fluid from said accumulator means connectingthe valve outlet to. saidaccumulator inlet orifice, with capacity to feed said lnbriating oil into said accumulator at a flow rate which is greater than the flow rate attainable: through said outlet orifice to said drain, a pressureswitching. device, means connecting said accumulator to said pressure switching device, an actuating means, in, said. pressure switching device which is responsive to thelubricating oil pressure accumulated". in said accumulator, said actuating means being delayed in its operation with respect to the operation of said fuel feed regulating means by thedraining of said lubricating oil out of. said outlet orifice associated with said accumulator, and signalling means connected to said pressure switching device for operation in response thereto Refereuees- Citedin the file of this patent UNITED. STATES PATENTS- Hillis- Mar. 30,1937 Le.-lair- Jan. 26, 1954 

